Constriction of the fetal ductus arteriosus is rare and usually attributed to medications or CHD. We describe a 24-year-old multigravida at 33 weeks 5 days gestation with echocardiographic findings of severe ductal constriction, a dilated, hypertrophied and hypocontractile right ventricle, and severe tricuspid regurgitation following BC powder® use. Treatment with Digoxin and oxygen resulted in a progressive 71% reduction in peak systolic ductal gradient, improved right ventricular function, and decreased tricuspid regurgitation.